A mother and her boyfriend on Tuesday pleaded not guilty to murder and assault on a child, stemming from the death of a 3-year-old girl found in the mother's Napa apartment.

Napa County District Attorney Gary Lieberstein said Sara Kreuger, 23, and her boyfriend, Ryan Scott Warner, 26, entered the pleas in court after being charged in early February with the brutal murder of Kreuger's daughter, Kayleigh Slusher.